I guess one limitation of the embedded youtube videos is that nobody can see the video description:

Jonathan Bristow (also known as "Twilighte" in the little Oric World) has been responsible for some of the best pieces of software ever released for the Oric computers such as Zip'n Zap and Magnetix, but also some ports from other machines like Pulsoids, Stormlord, or Impossible Mission.

He unfortunately passed away in May 2013, and despite his efforts was not able to release some of the games he had started.

This is a short video showing one of the last prototypes of OType, which started as an horizontal shooter in the R-Type family (thus the name), before moving to a vertical scroller when he developed the AIC color system, this time inspired by the game SWIV (Silkworm IV), where the player could choose between sequences in planes, jeeps or as a commando soldier.

This demo version is relatively playable, the menus are partially working, including credits and highscores, and show that it would support various input methods and joystick interfaces.

Two players can play together, collision detection and hits are fullly functional, but sometimes trigger some crashes - which is why I limited the amount of shooting in the demo -.

Hope you like it, and who knows... maybe somebody will complete it one day?

(The music is from the C64 version of the 1942 game, which seemed fitting with the video environment).

For the details, Chema is correct: It is AIC; so the scroll vertically need to be in multiple of two steps, sprites move by 6 pixel laterally, there's no attribute conflicts because it's AIC so all the attributes are on the left side of the play field.

Regarding the source codes, they are not lost, but there's some archiving/sorting to do/finish.

At least one thing helps us: Pulsoids and earlier games were 100% written either on the real hardware or using his own cross assembler which Jede had to write a special converter for because nobody could understand the syntax. Fortunately at some point he switched to XA so at least the code would not be alien to us.

Fortunately at some point he switched to XA so at least the code would not be alien to us.

Mmmm not sure about that. Twi's code has always been alien to me but at least the syntax is known, so we can assemble and test things

I really think it should not be very difficult to complete O-Type, as long as it keeps just as a two player vertical scrolling shmup, and nothing much more complicated.

Music is another story. It might be time to start exploring how to achieve those effects. My sfx&music engine (the one in Oricium and Blake) is far too simple (thus also compact) to do those things... I am sure you, Dbug, know much more about how to do those.

Twilighte did wonders with the Oric's AY... Pity we don't have the information about how he did those things. He experimented with many many different techniques. One of them was adding 'colour' to the notes by using the Envelope generator at certain frequencies. Unfortunately, that means no volume control (which, for our Orics, means disturbing everyone in a radius of 10Km).
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I always end up shocked in awe with his Impossible Mission theme:

That vertical scroll is made in steps of two lines, else AIC won't work. I also bet horizontal movements are limited to scans if inverse bits are set. Else it is not necessary, but it would be obviously much slower.

For the details, Chema is correct: It is AIC; so the scroll vertically need to be in multiple of two steps, sprites move by 6 pixel laterally, there's no attribute conflicts because it's AIC so all the attributes are on the left side of the play field.

Oki, this makes sense, thanks for the explanation!

One could have a 3 horizontal pixels scrolling precision by renouncing to use the inversion bit and using 3 pixels wide "pixels". This would be quite blocky and would seriously reduce the number of perceived colors that AIC allows through dithering and could be interesting for some games but clearly this would not have allowed the precise graphics he drew for O-Type.

Balls, I wish we had sources for these things. Just more motivation to crack into the monitor and just read the assembly... listening it seems he also coded parameter-based effects, such as a delay and reverb as well ..

Well, since he was coding in assembly language we just need a disassembler to get the sources.
Sure they are not commented nor structured but they are still his original code.

I've only been in the Oric community for a couple of months now, but already I am completely in awe of Twilighte. That OType demo is amazing.

Regarding unfinished games, I'm also very much in awe of the Wurlde demo, the one where it starts outside the castle and you can walk around between the various outside locations. The file I mean is called wurldedemo2.zip. Not sure if that was the latest Wurlde demo, but it is pretty cool.

Obviously most things he produced were amazing. They stand there as a challenge for the rest of us, and will do forever I hope. I'm certainly eager now to give Oric game programming a go as soon as I've got JOric to an initial user friendly release.

I think that CCSXS demo image was constructed using the TGS, or at least some of those tiles look familiar .. and I agree, we should really try to finish Twi's games .. Wurlde is mind-blowing, and OType just seems like it needs the last 5% of the effort to wrap it into a release.

OType just seems like it needs the last 5% of the effort to wrap it into a release.

Actually, what we see was just meant to be a sequence of O-Type.
I agree it has enough qualities to be released as a single game, just wanted to point that if you want to have an idea of what it was meant to be, see the CEO-Mag http://www.oric.org/ftp/ceo/ceomag/spec ... ristow.pdf

Twilighte did wonders with the Oric's AY... Pity we don't have the information about how he did those things. He experimented with many many different techniques. One of them was adding 'colour' to the notes by using the Envelope generator at certain frequencies. Unfortunately, that means no volume control (which, for our Orics, means disturbing everyone in a radius of 10Km).

.../...

I always end up shocked in awe with his Impossible Mission theme:

I couldn't agree more with this Chema, it's just an awesome piece of chiptune music, with instruments sounds with a rarely heard quality !!!

I really had my mind blown when I heard the bass sound starting at 1:52 on the video !!!

I recall I found back some data for this tune, but it didn't exactly match the one in the video. Can't recall how different it was, but I can try and find it back if you wish.

Hi Symoon,

It would really be great if you could post any data you found for this tune because it is one of the BEST AY-3-891x/YM-2149 chiptunes I have ever heard, in terms of instrument sounds !!

And you people are right, these are actually clever tricks with the enveloppe generator, using a very short enveloppe period and therefore modulating the square wave at a very high frequency.

There is an AWESOME, MUST-READ article on the subject in the "Tutorials" section of the Arkos Tracker site that explains it in a level of detail I have not seen anywhere else, as it has supporting sound clips with videos showing the waveforms used:Understanding the AY

Ah, and speaking of feats with the AY-3-891x/YM-2149 chip, here's an awesome tune as well, played on an YM2149 through an Arduino, the sounds are really stunning, I especially love the "detuned lead voice" sound, and it also uses as well different levels of fast arpeggios to add nice effects / sound colours (beware... you're going to get your ears blown, you won't believe this is an AY/YM tune !!!): Youtube - YM2149 Midi Synth

But going back to Twilighte, it would be very nice to get the data (even it its not the final version) for his Mission Impossible tune !!

Last edited by laurentd75 on Sat Jun 02, 2018 10:53 pm, edited 2 times in total.

Ok, I found back the disk with Impossible Mission tune, not exactly the same and playing slower.
Two questions:

1- where do I post it? This is an O-Type thread Interestingly enough, the old Impossible Mission development thread ends with... O-Type postsviewtopic.php?f=20&t=499&start=135
So, here, there, elsewhere?

2- I also made a mp3 of the tune, with a fake stereo (simply created by a little delay between left annd right channels). Anyone interested?

My goal at the time was to try and find the original tune, play it Oric channel by Oric channel, and try to make a real stereo mix. Not sure I would have been able to achieve this, but I gave up when I didn't find the exact same tune.

I guess we should avoid just trying to shove everything in one category and post new threads for relevant stuff, with musical things going in the relevant Oric Audio category, and old games prototypes in the Game category.

Do you want to turn your Oric into a synthesiser, and never use it for anything else? . Because this is how we get synthesisers.

No, I'll keep my Oric for games and programming

But now that you mention synthetisers, I actually have a bunch of AY/YM chips and I alread built a circuit similar (although more basic) to the one shown on this video, on a breadboard, connected to an Arduino Nano and using a 2 MHz crystal (this latter part is actually optional as you can use the Arduino timers to generate the clock signal).

What I would very much like to achieve is to build a twin AY/YM synthetizer (to have 6 channels instead of just 3) , with a MIDI interface, and to design some "sound banks" so I could actually use it as an expander and connect it to my MIDI keyboard... But this is just one of the numerous projects I currently have on hold with Arduino, I never get enough time to do the projects I'd like to do...